Find-PlaceholderItemByKeyName.ps1

param(
    [string] $PlaceholderKey = "col-wide-2"
)

# 1) Load master database
$db = [Sitecore.Configuration.Factory]::GetDatabase("master")
if (-not $db) {
    Write-Error "ERROR: Could not load the 'master' database."
    exit 1
}

# 2) Known IDs
$fieldId    = [Sitecore.Data.ID]::Parse("{7256BDAB-1FD2-49DD-B205-CB4873D2917C}")
$templateId = [Sitecore.Data.ID]::Parse("{5C547D4E-7111-4995-95B0-6B561751BF2E}")

# 3) Get the Placeholder Settings folder
$rootItem = $db.GetItem("/sitecore/layout/Placeholder Settings")
if (-not $rootItem) {
    Write-Output "ERROR: '/sitecore/layout/Placeholder Settings' not found."
    exit 1
}

# 4) Pull all descendants into an array
$allDesc = @($rootItem.Axes.GetDescendants())

# 5) Filter by template + field value
$matches = @(
    $allDesc |
    Where-Object {
        $_.TemplateID -eq $templateId -and
        $_.Fields[$fieldId].Value -eq $PlaceholderKey
    }
)

# 6) Output based on how many we found
switch ($matches.Count) {
    1 {
        # Exactly one match: output its ID
        Write-Output $matches[0].ID
    }
    0 {
        # No matches
        # Write-Output "No placeholder-definition found for key '$PlaceholderKey'."
    }
    default {
        # More than one
        $ids = $matches | ForEach-Object { $_.ID } -join ", "
        Write-Output "Multiple definitions found for key '$PlaceholderKey': $ids"
    }
}

Returns the ID of found placeholder definition item (or nothing at all)